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Skink smarts Lizards are quick to find safe refuges in environments that mimic their home, dispelling the long-held myth that reptiles are slow learners, a new study has found.

Previous work on lizards' spatial learning had almost exclusively been conducted in laboratory settings in an attempt to understand the cues lizards use to learn spatial tasks.

"These studies had potentially constrained lizards from learning the tasks they had been set," says biologist and lead author Daniel Noble from Macquarie University.

With fewer cues to show them where they were, the lizards may have struggled with the tests, leading to suggestions that they weren't as bright as warm-blooded animals.

"In a bid to create a more ecologically relevant study, we put our lizards in conditions that mimic the kind of conditions they would encounter in the wild," he says.

"Instead of demonstrating poor cognitive abilities, we found that they were able to correctly learn a spatial task and, more suprisingly, also a spatial reversal task in a little over a week."

Taking refuge

The study, published in the journal Biology Letters, tested 60 male eastern water skinks (Eulamprus quoyii) to determine whether they could learn the location of safe refuges in an outdoor enclosure.

"Males were chosen because we have some evidence to suggest that they are better spatial learners than females," explains Noble. "They are also more active and have larger home ranges than females during the breeding season and this likely puts greater pressure on them to know the locations of refuges in their environment."

The skinks were placed in large outdoor tubs containing mulch substrate and a water bowl along with three separate stacks of terracotta roofing tiles, which were used as refuges.

In the spatial learning task, each lizard was trained to locate a randomly chosen safe refuge over four days. Researchers entered the tubs and acted as predators by following the lizards from different points around their enclosure until they sought refuge under one of the tile stacks.

If it was the right refuge, the lizards were left alone to reinforce the positive association with the safe refuge; if not the tile was lifted and the lizards followed again until they made the right choice.

In the reversal learning task, a new safe refuge was chosen by the researchers, and the lizards were forced to 'unlearn' their previous association, using a similar process. This task allowed the researchers to determine whether the skinks' spatial learning abilities are flexible.

"Thirty-two percent of the lizards learned both tasks within ten days," says Noble. "It was remarkably fast, compared with the results of previous studies that indicated lizards had a poor capacity to learn very simple spatial tasks."

Survival instinct

"Our results make a lot of sense because lizards are often faced with predatory threats in the wild where they are required to escape to a refuge to avoid being eaten.

"This requires the knowledge of the spatial locations of refuges within their environment and to be able to flexibly adjust the use of the refuges depending on whatever contingencies arise. "

Further work is needed to determine how they learn and whether they retain that knowledge over the long term, he says.